Mixing machine and the like



July 20 1926.

O. MITCHELL MIXING MACHINE AND THE LIKE Filed Nov. 9, 1925 Patented July 20, 1926.

UNITED PATENT OFFICE.

MACHINERY COMPANY, GREAT BRITAIN.

(1920 LIMITED, on LoNDoN, ENGLAND, A COMPANY 0E MIXING MACHINE AND THE LIKE Application filed. November 9', 1925, serial No. 67,959, and at Great Britain October 1, 1925.

This invention relates to mixing machines such as are used for example in the produc tion of concrete and similar mixtures for building and constructional work.

More particularly the invention is concerned with mixing machines of the rotary drum type in which the drum is mounted so as'to berotatable around an inclined axis during the mixing operation and to be tilted into suitable positions for charging and discharging.

In machines of this kind the drum is provided with a tubular bearing rising from the middle of the bottom of the drum and adapted to receive a stationary shaft mounted on the usual supporting yoke, the drum being usually provided with mixing and lifting blades or members secured to the interior thereof.

With such drums difliculty is experienced in obtaining a thorough mixing of the ingredients due sometimes to the fact that the materials to be mixed are liable to pack together and escape contact with the mixing blades.

Now the main object of the present invention is to obviate this defect to the end of obtaining a mixture in which the various ingredients are thoroughly intermingled and the full batch of concrete or the like discharged at each discharging operation.

WVith this end in view and such others as may hereinafter appear or are incidental thereto the. invention may be said to comprise a mixing drum of the type referred to in which the stationary shaft carried by the usual yoke passes through the upstanding bearing in the drum and is provided with a member or members adapted to cut or mix or assist in mixing the ingredients of the mixture as the drum is rotated.

The aforesaid member or members may be secured directly to said shaft or may be mounted on a sleeve bush bracket or the like secured to the shaft. They may be disposed at any desired angle to the longitudinal axis of the shaft and means may if desired be provided for adjusting the angular relationship between the member or members and the shaft. i

In order that the invention may be clearly understood reference will now be made to the accompanying drawing wherein a preferred embodiment thereof has been illustrated' by way of example.

Figure 1 illustrates avertical section of a mixing drum having the invention applied thereto and Figure 2 is a plan view thereof.

Referring to" the drawings wherein thesame reference numerals indicate the same or similar parts 1 is the mixing drum which may be of any desired shape and is provided as usual with a tubular bearing 2 rising from the middle of the bottom of the drum said bearing receiving a stationary shaft 3 carried by the usual supporting yoke 4c.

The drum is provided with an annular toothed member 5 with which one or more driving pinions 6 engage whereby the drum is rotated.

During rotation the drum occupies an inclined position and the materials being mixed therein are thrown about the drum the mixing operation being assisted by mixing blades 7 secured to the interior of the drum. 7

With such drums it has been found that the ingredients being mixed therein tend to pack together at the bottom of the drum and in consequence thereof the ingredients are not thoroughly intermingled resulting in an imperfect batch of mixed material being obtained from the drum. Furthermore the ingredients being mixed are generally of a sticky nature and frequently stick to the bottom of the drum and are not discharged from the drum with the main batch of mixed material.

To obviate such defects according to the present invent-ion there is provided in the interior of the drum a member or members adapted to cut or mix or assist in mixing the ingredients of the mixture as the drum is rotated.

In the embodiment of the invention shown on the drawing a plurality of such mixing members 8 are provided said members being shaped preferably as turbine blades and being secured as by bolts or the like to flanges 9 on a bush or sleeve 10 secured to the stationary shaft 8.

The holes in the mixing members 8 and/ or the holes in the flanges 9 for receiving the securing bolts are preferably elongate whereby the angularity of the said members with respect to the shaft 3 may be varied as desired. j

Furthermore if desired the mixing members 8 may be mounted on the shaft 8 in such manner as to be capable of being moved into the operative and inoperative positions.

As the mixing members 8 extend in proximity to the bottom of the drum the ingredients being mixed in the drum cannot pack therein and cannot stick to the bottom of the drum whilst the main batch of material is being discharged therefrom with the result that the ingredients are thoroughly intermingled and a complete batch of mixed material is discharged from the drum on the completion of the mixing operation.

IVhat I claim and desire to secure by Letters Patent of the United States is 1. In a rotatable concrete mixing drum or members secured to said having an upstanding bearing through which a stationary shaft extends, a member shaft and projecting into proximity to the bottom of the drum and serving to prevent packing of the concrete in the bottom of the drum, and means whereby the angular relationship between said member or members and said shaft may be varied as desired.

2. In a rotatable concrete mixing drum having an upstanding bearing through which a stationary shaft extends, a sleeve secured to said shaft, flanges on said sleeve, a plurality of mixing members in the form of turbine blades, means whereby said blades can be secured to said flanges and means whereby the angular relationship between said blades and said shaft can be varied.

In testimony whereof I have signed my name to this specification.

ORMEROD MITCHELL. 

